aswitch in CustomerX, Site 1, willbuild a spanningtree on theswitches at that site without considering
convergenceparameters based on Customer Xs switch in Site 2. This could result in the topology shown in
theLayer 2 NetworkTopology without Proper Convergence figure.
Figure 12: Layer 2 Protocol Tunneling
Figure 13: Layer 2 Network Topology Without Proper Convergence
Inan SP network, you can use Layer 2 protocol tunneling to enhance the creation of EtherChannels by
emulatinga point-to-point network topology. When you enable protocol tunneling (PAgP or LACP) on the
Catalyst 2960-XR Switch VLAN Configuration Guide, Cisco IOS Release 15.0(2)EX1
130 OL-29440-01
Configuring IEEE 802.1Q and Layer 2 Protocol Tunneling
Layer 2 Protocol Tunneling Overview